MODEL 1525
INERTIAL SURFACE MOUNT ACCELEROMETER
•
•
•
•
•
•
•
•
•
•
•
•
•
Typical Non-Linearity
___ 0.1% of Full Scale
Low Noise: 8 μg/√Hz typical for 2g Full Scale
Built In DV Self-Test Function
Zero Cross Coupling by Design
J Lead Packaging for Max Repeatability
Responds to DC and AC Acceleration
-40 to +85°C Operation
Low Power +5 VDC, 5 mA
±4.0V Differential Output
Integrated Sensor & Amplifier
Internal Temperature Sensor
Nitrogen Damped, Hermetically Sealed
Lid & Case Serialized for Traceability
• RoHS Compliant
0.350
AVAILABLE G-RANGES
Full Scale
Acceleration
±2g
20 Pin
JLCC
1525J-002
20 Pin
LCC
1525L-002
±5g
1525J-005
1525L-005
± 10 g
1525J-010
1525L-010
± 25 g
1525J-025
1525L-025
± 50 g
1525J-050
1525L-050
± 100 g
1525J-100
1525L-100
LCC package by special order only
"J" SUFFIX
PACKAGE
0.350
Positive
Acceleration
0.350
"L" SUFFIX
PACKAGE
0.350
0.165
Positive
Acceleration
0.105
DESCRIPTION
The Model 1525 is a low-cost, integrated accelerometer for use in tactical navigation, seismic, and zero to medium frequency
instrumentation applications that require high repeatability and low noise. The 1525 was designed for maximum stability
while maintaining best-in-class noise performance. Each miniature, hermetically sealed package combines a MEMS capacitive
sense element and a custom integrated circuit that includes a sense amplifier and differential output stage. It is relatively
insensitive to wide temperature changes and gradients. Each device is marked with a serial number on its top and bottom
surfaces for traceability. A calibration test sheet is supplied with each unit showing the measured bias, scale factor, linearity,
operating current, and frequency response.
ZERO (DC) TO MEDIUM FREQUENCY APPLICATIONS
PERFORMANCE
By Model: VDD=VR=5.0 VDC, TC=25°C.
Model
Number
UNITS
1525-002
1525-005
1525-010
1525-025
1525-050
1525-100
Input
Range
g
±2
±5
±10
±25
±50
±100
Frequency
Response
(Minimum, 3 dB)
Hz
0 – 300
0 – 300
0 - 500
0 - 1100
0 – 1100
0 - 1250
Sensitivity,
Differential
mV/g
2000
800
400
160
80
40
Output Noise,
Differential
(RMS, typical)
μg/(root Hz)
7
12
18
25
50
100
Vibration
Rectification @ 100Hz
TYP
MAX
mg/g2 (RMS)
0.30
0.75
0.20
0.40
0.12
0.20
0.05
0.10
0.03
0.06
0.02
0.05
Max.
Mechanical
Shock (0.1 ms)
g (peak)
2000
5000
100g parts are tested from -65 to +65g.
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE
Silicon Designs, Inc. • 13905 NE 128th Street, Kirkland WA 98034 • Phone: 425-391-8329 • Fax: 425-391-0446
www.silicondesigns.com
[page 1]
08-May-2015
Model 1525
PERFORMANCE - ALL VERSIONS
PARAMETER
Bias Calibration Error1
Bias Temperature Coefficient (TC= -40 to +85°C) 1
Scale Factor Calibration Error 1, 3
Scale Factor Temperature Coefficient (TC= -40 to +85°C) 1
Non-Linearity 3
RMS Model Residual (+/- 1g, -30 to +90°C)
In Run Bias Stability (Allan Variance minimum)
Velocity Random Walk
Long Term Bias Stability 4
Long Term Scale Factor Stability 4
Turn-On Transient (in less than 0.5ms)
Output Impedance
Recommended Operating Temperature
Operating Voltage
Operating Current (IDD+IVR) 1
Input Axis Misalignment
Mass
MIN
-50
-100
-40
4.75
TYP
0.1
0
0.5
0
0.1
100
3
2.5E-4
150
300
150
90
MAX
0.5
50
1
100
0.5
200
(750)
(1000)
+85
5.0
5.25
5
6
6
15
LCC 0.62, JLCC 0.68
UNITS
% of FS
(PPM of FS)/°C
%
PPM/°C
% of FS
PPM of FS
PPM of FS
X FS - m/sec/sqrt(hr)
PPM of FS (+1 sigma)
PPM (+1 sigma)
PPM of FS
ohms
°C
volts
mA
mrad
grams
All Models: Unless otherwise specified VDD=VR=5.0 VDC, TC=25°C, Differential Output, J-lead package
MAXIMUM RATINGS *
Case Operating Temperature 2
Storage Temperature
Voltage on VDD to GND
Voltage on Any Pin (except DV) to GND 3
Voltage on DV to GND (Self Test)
Power Dissipation
Cleaning
-55 to +125°C
-55 to +125°C
-0.5V to 6.5V
-0.5V to VDD+0.5V
±15V
50 mW
The sensor cannot be ultrasonically cleaned
* NOTICE: Stresses greater than those listed above may cause permanent damage to the device. These are maximum stress
ratings only. Functional operation of the device at or above these conditions is not implied. Exposure to absolute maximum
rating conditions for extended periods may affect device reliability and lifespan.
Note 1: Tighter tolerances may be available on special order.
Note 2: Voltages on pins other than DV, GND or VDD may exceed 0.5 volt above or below the supply voltages provided the
current is limited to 1 mA.
Note 3: 100g and greater versions are tested from -65 to +65g for scale factor, linearity and vibration rectification.
Note 4: Tested as: Power cycle 100x, Shock 500g all axis, storage at -45 and 85°C, temperature cycle 10x -40 to 120°C, vibration
90%FS 125—1000Hz band.
RECOMMENDED MODELS
•
•
•
Applied Acceleration = Bias + BiasTC*T+ BiasTC2*T**2+ (5.00/VR)*(SF+ SFTC*T+ k2*Vout)*(Vout), where parameters are
the least squares fit with T = (Measured Temp – 25C) and Vout = (Vaop-Vaon).
The term (5.00/VR) can be ignored if calibrated in a production IMU with a repeatable reference or if the A/D reference
and the VR voltage are derived from the same source.
When the internal Temp Sensor is used, a recommended model is T = Tbias + Tsens*Vit + Tsens2 * Vit**2, where the
temperature parameters are the least squares fit to (oven temperature-25C) and Vit is a voltage proportional to the
current out of IT.
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE
Silicon Designs, Inc. • 13905 NE 128th Street, Kirkland WA 98034 • Phone: 425-391-8329 • Fax: 425-391-0446
www.silicondesigns.com
[page 2]
08-May-2015
Model 1525
OPERATION
5
OUTPUT VOLTAGE
The Model 1525 produces a differential output voltage, the value of which varies
with acceleration as shown in the figure, right. Two reference voltages, +5.0 and
+2.5 volts (nominal), are required; the output scale factor is ratiometric to the +5.0
volt reference voltage relative to GND, and both outputs at zero acceleration are
nominally about 50 mV below the +2.5 volt input. The sensitive axis is
perpendicular to the bottom of the package, with positive acceleration resulting
from a positive force pushing on the bottom of the package.
4
AO
N
P
AO
3
(Di
ffer
ent
ial
On
ly
2
1
0
-Full Scale
0
)
+ Full Scale
ACCELERATION
SIGNAL DESCRIPTIONS
AOP
(vdd)
GND
(gnd)
(vdd)
VR
VDD and GND (power): Pins (14) and (19) respectively. Power (+5 Volts DC) and ground.
AOP and AON (output): Pins 12 and 16 respectively. Analog output voltages
3
2
1 20 19
proportional to acceleration. The AOP voltage increases (AON decreases) with
18 (gnd)
DV 4
positive acceleration; at zero acceleration both outputs are nominally equal to the
+2.5 volt reference. The device experiences positive (+1g) acceleration with its lid (gnd) 5
17 2.5V
facing up in the earth’s gravitational field. Use of differential mode is strongly
16 AON
TOP VIEW
recommended for both lowest noise and highest accuracy operation. Voltages can (gnd) 6
be measured ratio-metrically to VR for good repeatability without requiring a
7
15
separate precision reference voltage for an A/D.
14 VDD
IT 8
DV (input): Pin 4. Deflection Voltage. Connect to the 2.5 Volt pin for best
9 10 11 12 13
repeatability. A test input that applies an electrostatic force to the sense element,
simulating a positive acceleration. The nominal voltage at this pin is ½ VDD. DV
voltages higher than required to bring the output to positive full scale may cause
device damage.
VR (input): Pin 3. Voltage Reference. Tie to a good reference (not directly to VDD) for best scale factor repeatability. A 0.1μF
bypass capacitor is recommended at this pin. VR current is less than 100 uA.
2.5 Volt (input): Pin 17. Sets internal and output common mode value. Tie to a resistive voltage divider from +5 volts. A 0.1μF
bypass capacitor is recommended at this pin.
IT (output)/ClkIn (Input): Pin 8. Temperature dependent current source or optional external clock input. Tie to VDD if not used.
Special Use Pins: Pins 9 and 11 should be tied to VDD; Pins 2,5,6 and 18 to GND; Pins 1,7,10,13,15, and 20 are reserved and
should remain unused.
RECOMMENDED CONNECTIONS
The 2.5V input (pin 17) may be driven from a resistive divider.
DEFLECTION VOLTAGE (DV) TEST INPUT: This test input
applies an electrostatic force to the sense element to
simulate positive acceleration. For most repeatable
operation, DV should be tied to the 2.5V input so stray
voltage on it will not affect the output.
TEST INPUT
ESD and LATCH-UP CONSIDERATIONS:
(OPTIONAL)
The model 1525 accelerometer is a CMOS device subject to
damage from large electrostatic discharges.
Diode
protection is provided on the inputs and outputs, and it is
0.1uF
not easily damaged, but care should be exercised during
handling. However, individuals and tools should be
grounded before coming in contact with the device.
Although the 1525 is resistant to latch-up, inserting a 1525
into or removing it from a powered socket may cause damage.
5K
4
0.1 uF
17
+ 5V
REF
+ 5V
Power
3
VR
14
VDD
11
0.1 uF
9
AOP
DV
1525
AON
2.5V
IT
5K
2
GND
5
19
6
12
16
OUTPUT (POSITIVE)
OUTPUT (NEGATIVE)
8
18
RT
2K
TEMPERATURE
VOLTAGEOUT
(OPTIONAL)
SIGNAL CONNECTIONS
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE
Silicon Designs, Inc. • 13905 NE 128th Street, Kirkland WA 98034 • Phone: 425-391-8329 • Fax: 425-391-0446
www.silicondesigns.com
[page 3]
08-May-2015
Model 1525
INTERNAL TEMPERATURE SENSING
The model 1525 accelerometer contains a temperature dependent current source whose output is on pin 8. This signal is useful
for measuring the actual internal temperature of the accelerometer. By using it, the previously characterized bias and scale
factor temperature coefficient values can be used to correct for instantaneous on-chip temperature, providing more accuracy
with changing temperature than with an external sensor. The nominal output current at 25°C is about 500 (±200) μA and the
nominal sensitivity is about +1.5 (±0.5) μA/°C. RMS noise is equivalent to about 0.25° C of temperature. If unused, pin 8 should
be connected to VDD.
PACKAGE DIMENSIONS
The J-lead package is the standard package for the 1525 for maximum repeatability. The 1525 is also available in the L-lead
package by special order where minimum package height is important.
"J" SUFFIX PACKAGE (20 PIN LEADED CHIP CARRIER)
*T
R
F
K
*U
N
P
B
A
TERMINAL 20
Positive
Acceleration
A
*M
D
NOTES: 1.
2.
3.
4.
TERMINAL 1
DIM
A
B
D
F
K
*M
N
P
R
*T
*U
INCHES
MIN
MAX
0.342 0.358
0.346 0.378
0.095 0.115
0.050 BSC
0.010 RTYP
0.048 TYP
0.050 0.070
0.017 TYP
0.023 RTYP
0.085 TYP
0.175 TYP
MILLIMETERS
MIN
MAX
8.69
9.09
8.79
9.60
2.41
2.92
1.27 BSC
0.25 RTYP
1.23 TYP
1.27
1.78
0.43 TYP
0.58 RTYP
2.16 TYP
4.45 TYP
CONTROLLINGDIMENSION: INCH.
LID IS ELECTRICALLYTIED TOTERMINAL 19 (GND).
* DIMENSIONS 'M', 'T' & 'U' LOCATEACCELERATION SENSINGELEMENT'S CENTEROF MASS .
TERMINALS AREPLATED WITH 60 MICRO-INCHES MIN GOLD OVER80 MICRO-INCHES MIN NICKEL.
(THIS PLATINGSPECIFICATION DOES NOT APPLY TOTHEMETALLIZED PIN-1 IDENTIFIERMARK ON
THEBOTTOM OF THEPACKAGE).
5. PACKAGE: 90%MINIMUM ALUMINA (BLACK), LID: SOLDERSEALED KOVAR.
SOLDERING RECOMMENDATIONS
RoHS Compliance: The model 1525 does not contain elemental lead and is RoHS compliant.
F
G
Pre-Tinning of Accelerometer Leads is Recommended: To prevent gold migration embrittlement
of the solder joints, it is best to pre-tin the accelerometer leads.
LCC Solder Contact Plating Information: The plating composition and thickness for the solder
pads and castellations on the “L” suffix (LCC) package are 60 to 225 micro-inches thick of gold
(Au) over 80 to 350 micro-inches thick of nickel (Ni) over a minimum of 5 micro-inches thick of
moly-manganese or tungsten refractory material. The J-Lead package top layer is 100 to 225
microinches thick of 99.7% gold (Au) over 80 to 350 microinches thick of electroplated nickel (Ni).
Cleaning: The sensor must not be cleaned with an ultrasonic bath.
F
E
A
C
D
B
DIM
A
B
C
D
E
F
G
Inch
.230
.430
.100
.033
.050
.013
.120
mm
5.84
10.92
2.54
0.84
1.27
0.33
3.05
SPECIFICATIONS SUBJECT TO CHANGE WITHOUT NOTICE
Silicon Designs, Inc. • 13905 NE 128th Street, Kirkland WA 98034 • Phone: 425-391-8329 • Fax: 425-391-0446
www.silicondesigns.com
[page 4]
08-May-2015